Composition for the prevention or removal of insoluble salt deposits

ABSTRACT

The present invention provides compositions, in particular blocks, tablets and gels, for the prevention or removal of insoluble salt deposits comprising: a) an organic acid with two carboxylic acid functional groups obtainable by fermentation, selected from the list of itaconic acid, itaconic acid anhydride, succinic acid, succinic anhydride and combinations thereof, and b) at least one compound determining the release of said acid from said composition, said compound is selected from a list comprising: i) a hygroscopic compound, ii) a carbonate source, iii) an acid solubility retarding compound, iv) a compound with melting point situated between 60° C.-95° C., and combinations thereof. The invention further provides uses of the compositions for the prevention or removal of insoluble salt deposits. The invention also provides a method of manufacturing such compositions and a method for the prevention or removal of insoluble salt deposits with a product of the invention.

TECHNICAL FIELD

The present invention relates to compositions for the prevention orremoval of insoluble salt deposits. The present invention furtherrelates to use of compositions for the prevention or removal ofinsoluble salt deposits. The present invention further provides a methodfor the manufacturing of compositions for the prevention or removal ofinsoluble salt deposits and to a method to prevent or remove insolublesalt deposits using compositions according to the invention.

The present invention relates to the use of a composition comprisingitaconic acid, its anhydride, succinic acid, its anhydride, and orlactide and combinations thereof for the prevention or removal ofinsoluble salt deposits.

The present invention further relates to a toilet block, comprising acomposition comprising itaconic acid, its anhydride, succinic acid, itsanhydride, and or lactide and combinations thereof.

The present invention further relates to an effervescent tabletcomprising a composition comprising itaconic acid, its anhydride,succinic acid, its anhydride, and or lactide and combinations thereof.

The present invention further relates to an acid gel comprising acomposition comprising itaconic acid and or succinic acid combined witha rheology modifier.

Also, this invention relates to a composition comprising itaconic acid,its anhydride, succinic acid, its anhydride, and or lactide andcombinations thereof for the prevention or removal of insoluble saltdeposits

BACKGROUND

Water insoluble salts such as calcium and magnesium carbonates orsilicates or sulfates commonly referred to as limescale, but also bariumsulfate, calcium oxalate, calcium phosphate, iron oxide and the like arereadily formed in watery solutions when the conditions are right and mayeach represent particular challenges in relation to their removal.

Limescale or limestone is the hard, off-white, chalky deposit found inkettles, hot-water boilers and the inside of inadequately maintainedhot-water central heating systems. It is also often found as a similardeposit on the inner surface of old pipes and other surfaces where “hardwater” has evaporated.

These types of limescale differ slightly due to their origins. The typefound deposited on the heating elements of water heaters, laundrymachines, etc. has a main component of calcium carbonate, precipitatedout of the (hot) water. Hard water contains calcium (and oftenmagnesium) bicarbonate and/or similar salts.

Calcium bicarbonate is soluble in water, however at temperatures above70° C. the soluble bicarbonate is converted to poorly-soluble carbonate,leading to deposits in places where water is heated. Local boiling “hotspots” can also occur when water is heated, resulting in theconcentration and deposition of salts from the water. Likewise calciumsulfate is a common component of fouling deposits in industrial heatexchangers, due to its decreased solubility with increasing temperature.Silicate containing laundry and automatic dishwashing products may causea calcium or magnesium silicate deposit, which is especially difficultto remove (in contrast to calcium carbonate) from glassware.

The type found on air-dried cooking utensils, dripping taps and bathroomtiling consists of calcium carbonate mixed with all the other salts thathad been dissolved in the water, prior to evaporation. It can also befound on taps and water reservoirs (such as in the toilet) where hardwater has been continually running through and has deposited calciumcarbonate.

The presence of limescale presents several problems. Other than beingunsightly and harder to clean, limescale can impair the operation ofvarious components or damage them. In kettles, limescale acts as aninsulator, impairing heat transfer. Additionally, it can damage theheating element, which overheats due to accruing limescale. Limescalecan build up inside tubing, thus reducing water flow and necessitatinghigher electrical consumption for the circulation pumps, and eventuallyblocking the tubing. Expresso machine manufacturers recommend to descalethe machine (depending on the water hardness) every month or trimesterin order to avoid bitter taste development, machine malfunction andslowing down.

Other types of deposits formed by insoluble salts are beerstone andmilkstone. Calcium oxalate forms a major component of beerstone, abrownish precipitate that tends to accumulate within vats, barrels andother containers used in the brewing of beer. Beerstone is composed ofcalcium and magnesium salts and various organic compounds left over fromthe brewing process; it promotes the growth of unwanted microorganismsthat can adversely affect or even ruin the flavor of a batch of beer.Calcium oxalate is also formed during carbonation of raw sugar beetjuice before it undergoes crystallization. First, the juice is mixedwith hot milk of lime (a suspension of calcium hydroxide in water). Thistreatment precipitates a number of impurities, including multivalentanions such as sulfate, phosphate, citrate and oxalate, whichprecipitate as their calcium salts and large organic molecules such asproteins, saponins and pectins, which aggregate in the presence ofmultivalent cations.

Milkstone is a layer of scale mainly formed by cations like calcium andmagnesium originating from both milk and hard water. Besides giving theequipment an unclean appearance, milkstone could harbour and protectmicro organisms always present in raw milk and ready to multiply at ahigh rate. Since milk products are some of the most perishable majorfoods, cleaning and sanitization in that industry generally require thehighest standards. The main part of milk residue is easily removed byrinsing with water. However, the last part comprising the milkstone isoften harder to get rid of.

Several methods and products have been developed in order to remove someor all of these different types of deposits by insoluble salts, such aslimescale.

Generally, different types of descaling agents are used to removedeposits by insoluble salts. Descaling agents are either acids orcomplexing agents or both in one (e.g. carboxylic acids). They removeinsoluble deposits such as limescale by respectively dissolving thelimescale and or complexing its cationic constituents. Acids used asdescaling agents can be either mineral acids or organic acids. Below intable 1, the properties of some organic and mineral acids that are usedor can be potentially useful for descaling are shown.

TABLE 1 Properties of some organic and mineral acids used or potentiallyuseful for descaling. Solubility Solubility Trivial name water calciumsalt physical of acid 20° C. g/100 ml form Sourcing descaling pKa smellCompatibility label oxalic  14%   0.0007 powder Petro 1.3/4.3 ++ C, Xnmaleic >40% 2.9 powder Petro 1.9/6.3 +− Xi/Xn malonic >90% No datapowder Petro 2.9/5.7 +− Xn tartaric +−60%    0.04 powder Ferm  3/4.3 ++Xi fumaric  64% 1.4, 2%^(b) powder Petro  3/4.4 ++ Xi citric  60% 5%(1.Ca) powder Ferm − 3.1/4.8/6.4 ++ ++ Xi 0.09% (2-3.Ca) malic >80%  0.8%^(b) powder Petro + 3.4/5.1 +− −− Xn formic 100% 17   liquid Petro++ 3.8 −− −− C, Xn glycolic 100%  1.2% powder Petro −− 3.9 +− −− C, Xnitaconic  9.5% No data powder Ferm 3.9/5.1 ++ Xi lactic 100% 7%,3.1%^(b) liquid Ferm + 3.8 ++ ++ Xi gluconic >50% 3, 3%^(b) powder Ferm3.9 −− Xn succinic  7.7%    0.004%^(b) powder petro/ferm 4.2/5.6 ++ C,Xn glutaric  50% Soluble powder Petro 4.3/5.4 ++ Xi Acetic 100% 33.8 liquid petro/ferm + 4.8 −− −− C, Xn Lactide^(a) Insol.^(a) ^(a) PowderFerm / ++ ++ Xi phosphoric 100%  0.03 liquid Min ++  2.2/6.8/12.4 + − C,Xn sulfamic  29% No data powder Min ++ 0.1 +− +− C, Xn, Nhydrochloric >40% 75   liquid Min −9.3   −− C, T, N sulfuric 100% 0.3liquid Min −3    +− C, T ^(b)Lactide is a dimeric ester rather than anacid but readily hydrolyses to lactic acid. Data obtained frompresentations by Purac and complemented with various literature data.Properties listed include the solubility in water (pH 7, 20° C.), thesolubility of the calcium salt (mono, di, tri-salts, ^(b)as % anhydrousat 25° C.), their physical form, descaling effectiveness (Purac data),pKa value(s), smell, overall material compatibility (Purac data) andlabeling according to EU legislation.

Table 1 documents among other characteristics the water solubility ofdi- and tri-salts of polybasic carboxylic acids which tends to be (very)limited as compared to that of monocarboxylic acids, with maleic andglutaric acids as an exception to this apparent rule. No literature datawere found regarding the calcium salt of itaconic acid. Whereas themonocalcium salt of citric acid is water soluble (5%), the disalt andtrisalts are only sparingly or practically insoluble (0.09 g/l).

The majority of acids commercially used for descaling are mineral acidssuch as phosphoric, sulfamic, hydrochloric and sulfuric acid (cf table1). These are however classified as corrosive to the skin and the eyesand as environmentally hazardous or in case of phosphoric acid representa substantial eutrophication potential. Moreover they tend to be eitherfuming or cause a pungent smell and their overall material compatibilityis limited.

Organic acids have one, two or three carboxyl groups (note the pKavalues in table 1) and are usually less aggressive which is why acetic,citric and formic and more recently glycolic and lactic acid found theirway to the market.

Organic acids can be sourced from fermentation or from petrochemicalsynthesis. Citric and lactic acid for example are obtained byfermentation from renewable feedstock (typically molasses). The factthat many of these organic acids suitable for descaling action arerenewable is increasingly considered an environmental advantage asillustrated in life cycle analyses. However, some of these organic acidsstill show disadvantages.

For example, the iron and calcium salts of citric acid are said to beless soluble than those of glycolic acid, so they may precipitate ontothe treated surfaces, diminishing cleaning effectiveness of citric acid.

Acetic and formic acid have a pungent smell that is hard to cover withfragrance, which is a serious disadvantage.

Acetic acid, which may be sourced from fermentation or frompetrochemical synthesis, is renowned for its corrosivity to copper whichleads to the formation of toxic copper acetate (a fungicide) thusrendering acetic and vinegar unsuited for descaling coffee and expressomachines which often have a copper mounting tube for hot water or steam.Acetic acids will thus also be unsuited for all other surfacescomprising cupper.

Furthermore, the descaling activity of many organic acids is quite weak.Many organic acids either show efficiency in fast descaling or indescaling upon prolonged contact, but not both. Moreover a limitednumber of organic acids is available as a solid. These are hugedisadvantages as they put a restriction onto the development ofdescaling agents that offer an overall better efficiency.

There is a need for a descaling agent which is renewable, and whichshows a better efficiency than the existing products.

One specific application of descaling agents is their use in toiletblocks, since toilets often suffer from severe insoluble salt deposits.Traditionally toilet blocks in the past where designed to mask odors andhave a slight cleaning effect in the toilet. The two main typesmanufactured and marketed up until the late 1980's were the so calledrim and the in-cistern blocks, applied in the toilet bowl and the watercistern respectively. During the 1990's several new developments havebeen marketed, with the liquid rim containers coming on the market whichhas greatly increased the flexibility and number of ingredientsavailable to formulate with, and the solid block formulations have alsobeen expanded with products that have special properties (i.e. limescale inhibition, bleaching, cleaning efficiency, etc.).

There are different challenges to the formulation and manufacture oftoilet and cistern blocks as these are dependent on most of theingredients being supplied as practically water free chemicals,otherwise they might have a negative influence on the chemicalproperties of the block as well as the stability and compatibility withother ingredients included. The main manufacturing process for suchblocks is by extrusion of a pre-made dry mixture of all the ingredients.A crucial property for the manufacture of solid blocks however has beenthe extrusion properties of the anionic surfactants and in particulardry LAS (Linear Alkyl Benzene sulfonate). The sodium salt of LAS in dryform is available as a very hygroscopic powder, which means thatprecaution has to be taken in terms of handling and storage, but it isalso this product characteristic that makes it an excellent mainingredient in formulating solid extrude toilet blocks. The hygroscopicnature of LAS ensures that once the final product is exposed to water inthe toilet bowl or in the cistern it will create an outer layer ormembrane that slows down the overall solubility of the block therebyimparting a controlled release of all the active ingredients in theblock (source: Toilet block introductory Leaflet by Unger, 2008).Formulating rim and in-cistern blocks among others implies selectingsolubility retarding or “matrix” ingredients with a melting point at orjust above the extrusion temperature, which upon cooling will form ahomogenous solid block that will gradually and evenly set free itsactives over time, typically during several weeks for 50 to severalhundreds of flushes, more typically up to 500-800 flushes. Such formulascontain 25-50% LAS (typically 40%), 0-8% fatty alcohol sulfate (mainlyC₁₂₋₁₄, some C₁₆ in cistern blocks) or 0-5% highly ethoxylated fattyalcohol (e.g. C₁₆₋₁₈ with up to 50 mol ethylene oxide), 0-3.5% Coconutmonoethanolamide, 1% foam enhancing fatty alcohol ether sulfate, 0.05%paraffin oil, 5-6% fragrance and dyes and sodium sulfate as a filler.Low amounts of acids (e.g. 2% lactic acid or 10-20% citric acidanhydrate) have been incorporated as well as polymers. US2007191245A1for example describes the use in toilet blocks of polysuccinimide forpreventing or dispersing urine scale.

Effervescent toilet descaling tablets form an alternative approach fordescaling, targeting fast tablet disintegration (as opposed to toiletblocks) but long contact times (e.g. overnight). They are produced bytabletting and always contain an acid (usually sulfamic or citric acid)for dissolution of the immersed limescale and a carbonate source for theeffervescent system (sodium carbonate, bicarbonate, percarbonate, . . .). Formulating such tablets is all about finding the balance betweenfast dissolution on one hand and tablet strength and stability on theother. Low moisture content is of paramount importance, especially whenthe formula contains percarbonate bleach. A typical formula contains1-2% lauryl sulfoacetate or FAS, 1% FAEO C₁₆₋₁₈ 8EO, 40-50% citric orsulfamic acid, 20-30% sodium carbonate, some polyethylene glycols,fragrance, dye, and sulfate as a filler. Some formulations additionallycontain about 2% percarbonate bleach.

Products dedicated to periodical cleaning and descaling of automaticdishwashing machines usually are based on citric acid and a smallamounts of FAEO (e.g. C_(9-11, 4)EO), and additionally may contain somecorrosion inhibitor, solvents, PEG, phosphonates, fragrance and dye.

There is a need for a renewable low moisture and stabile descaling agentthat can be used in descaling block or tablet formulations and has abetter efficiency than the existing descaling agents used in toiletblocks and tabs.

It is an object of the present invention to provide a new descalingagent which is made of renewable material and which shows a betteroverall efficiency than the descaling agents known from the prior art.

It is also an object of the present invention to find a toilet blockcomprising a descaling agent, which is made of renewable material, islow moisture and stabile with a better efficiency than the existingdescaling agents used in toilet blocks.

SUMMARY OF THE INVENTION

The present invention aims to provide a solution for at least one of theproblems mentioned.

The first object is achieved by a composition of claim 1. In particular,the present invention provides a composition for the prevention orremoval of insoluble salt deposits comprising:

-   -   a) an organic acid with two carboxylic acid functional groups        obtainable by fermentation, selected from the list of itaconic        acid, itaconic acid anhydride, succinic acid, succinic anhydride        and combinations thereof, and    -   b) at least one compound determining the release of said acid        from said composition, said compound is selected from the list        comprising:    -   i) a hygroscopic compound,    -   ii) a carbonate source,    -   iii) an acid solubility retarding compound,    -   iv) a compound with melting point situated between 60° C.-95°        C., and combinations thereof.

The inventors found that an acid as described under a) could be combinedwith compounds acting as acid release regulating means as describedunder b). This is advantageous as it allows the manufacturing ofcompositions for both fast and slow release based an acid of renewableresources, in particular itaconic acid and/or succinic acid. In apreferred embodiment, the anhydride form is used. The acids andanhydrides prescribed are interesting from an ecological point of viewas they are readily degradable and obtainable from renewable resources.The acids are remarkably compatible with the functional compounds underb). The combination of a) and b) provides a synergistic effect. Theacids under a) do not impact the functionality of compounds under b).This has for effect that they can be used as mixing partners. Selectionsof a compound from the list under b) will provide access to compositionswith either slow or fast release of the acid under b). Both fast andslow release compositions for itaconic acid, itaconic acid anhydride,succinic acid, succinic acid anhydride have become available.

In a preferred embodiment, the organic acid is itaconic acid.

Itaconic Acid (CH₂:C(COOH)CH₂COOH, CAS 97-65-4, also called MethyleneSuccinic Acid, Butanedioic acid, Methylene Butanedioic acid,Propylenedicarboxylic acid; 2-Propene-1,2-dicarboxylic acid;) is a whiteanhydrous (<0.3%) hygroscopic crystalline dicarboxylic acid with amelting point of 166° C. It is soluble in water, ethanol and acetone.Its chemical structure is similar to that of succinic acid but with amethylene group substituted onto the carbon chain, the unsaturateddouble bond forming a conjugated system with the carbonyl group.

Itaconic can be converted into its anhydride as described in U.S. Pat.No. 5,260,456. Itaconic anhydride (CAS 2170-03-8,2-Methylenesuccinicanhydride) white crystals have a slightly acidic odor and a meltingpoint of 67-69° C. In contact with water the anhydride will hydrolyzeback to itaconic acid.

Itaconic acids primary application is in the polymer industry where itis employed as a co-monomer at a level of 1-5% in styrene butadieneresins and in acrylic latexes for textile, paper, and paintapplications. It is furthermore used to prepare acrylic fibers andrubbers, reinforced glass fiber, artificial diamonds and lens.

Itaconic acid was discovered as a distillation product of citric acid,but is now typically produced in a fungal fermentation at relativelysmall scale. Magnuson and Lasure (2004) give an extensive overview ofthe history and current status of itaconic acid. The first reportedbiological source of itaconic acid was the descriptively namedAspergillus itaconicus. Shortly thereafter, it was discovered that A.terreus produced itaconic acid. An efficient process for thefermentation of sucrose in molasses to itaconic acid using A. terreuswas patented in 1962. The reported yield is 70%,

Magnuson J K, and L L Lasure. 2004. “Organic Acid Production byFilamentous Fungi.” Chapter 12 in ADVANCES IN FUNGAL BIOTECHNOLOGY FORINDUSTRY, AGRICULTURE, AND MEDICINE, ed. Jan S. Tkacz and Lene Lange,pp. 307-340. Kluwer Academic/Plenum Publishers, New York, N.Y.

The inventors have surprisingly found that itaconic acid in acomposition according to an embodiment of the invention shows excellentdescaling activity and an overall excellent activity in the removal andprevention of insoluble salt deposits.

Furthermore, itaconic acid in a composition according to an embodimentof the invention is a very strong descaling agent in both fast descalingas well as descaling upon prolonged contact.

Furthermore, It can be produced through fermentation, and it is a fullyrenewable descaling agent. Furthermore, it is non-corrosive and has aneutral smell.

Furthermore, itaconic acid can be used as a solid state, stabile, lowmoisture ingredient for descaling activities, allowing polyvalent use.

Furthermore itaconic anhydride can be used as an agent releasing theabove itaconic acid upon contact with water, a property especiallyuseful in toilet blocks.

In a preferred embodiment, the compound selected from list b) is thehygroscopic compound. More preferably, the hygroscopic compound islactide, an anionic surfactant, or combinations thereof. In a preferredembodiment the hygroscopic compound is lactide. An example of ahygroscopic anionic surfactant is alkyl benzene sulfonate. In apreferred form, itaconic acid is in substantially dry form, i.e. with awater content of at most 5%, preferably at most 3%, more preferably atmost 1%, most preferably at most 0.5%.

Lactide (CAS 4511-42-6 and 95-96-5, also called cyclic dimer of lacticacid, Dilactide, L-Lactide, DL-Lactide,3,6-Dimethyl-1,4-dioxane-2,5-dione) on the other hand contains twomolecules of natural L(+)-lactic acid in the form of a ring. While mixedwith water, the ring is hydrolyzed back into two free L(+)-lactic acidmolecules that allow a delayed acidification of the medium, the pH dropto pH2 being completed after two hours. The inventor observed completedissolution at room temperature to require at least 3 hours whilestirring. The strong acidity released by lactide is due to the low pKaof lactic acid and to the release of two acidic functions per mole. Itis a white, almost odorless, virtually water-free (<30 ppm) veryhygroscopic powder with a melting point of 94-99° C.

Lactide is produced by double condensation of L(+)-lactic acid moleculesobtained by fermentation of natural sugar. After several solvent-freepurification steps, small white flakes of pure3,6-dimethyl-1,4-dioxane-2,5-dione are obtained (solid lactic acid).There are several methods to prepare lactic acid. Among the biologicalroutes is a process employing R. oryzae. The organism imports glucoseand exports lactate, an acid that is not a component or by-product ofthe citric acid cycle. Lactate is produced by the organism aerobically,and the commercial process requires agitation and aeration just as theother fungal organic acid processes do. The substrate for the R. oryzaeprocess is glucose, and the manufacturers are corn-processing companieswith readily available low-cost glucose. Lactic acid is recovered by thetechnologies used for the other organic acids, including precipitationfrom an alcoholic extract. In aqueous solution, lactic acid dimerizes toform lactide, an intermediate for the biodegradable plastic, polylacticacid (PLA). Until recently, lactic acid was used primarily in the foodindustry as a preservative, flavor enhancer, and acidulant. Thededicated Nebraskan PLA (“NatureWorks”) production site alone has aproduction capacity of 140.000 tons and PLA use in packaging iscurrently rapidly growing.

The inventor has surprisingly found that also lactide shows excellentdescaling activity and an overall excellent activity in the removal andprevention of insoluble salt deposits.

In a preferred embodiment, a composition according to the inventioncomprises 1-20% lactide, preferably 1-20% slow-release lactide asmeasurable by the pH-development of a 0.1 w/v % solution of theslow-release lactide in demineralized water at 25° C. and the curvedepicting the pH versus time displaying a pH of 3.7 after 5 minutes, 3.2after 10 and 2.5 after 120 minutes.

Furthermore, It can be produced through fermentation, and it is a fullyrenewable descaling agent.

Furthermore, it is also non-corrosive and has a neutral smell and can beused as a solid state, stabile, low moisture ingredient for descalingactivities, allowing polyvalent use.

Lactide and Itaconic acid or its anhydride can be used separately as adescaling agent but they also show a highly efficient descaling activitywhen used in combination with each other.

Preferably, the insoluble salts deposits are selected from a groupconsisting of lime scale, beer stone, milk stone, barium sulfate,calcium oxalate and combination thereof.

Preferably, itaconic acid, its anhydride and or lactide and combinationsthere is present in the composition in a concentration of 5-60% m/m,preferably 20-40% m/m.

In such a concentration range, the composition of the present invention,is most effective.

In a preferred embodiment, the composition further comprises one or moreother acids.

Combined with other acids, the composition comprising lactide, itaconicacid and/or anhydride can be even more efficient.

In a preferred embodiment, the compound selected from list b) is thecarbonate source. More preferably, the carbonate source is sodiumcarbonate, bicarbonate or percarbonate.

In a preferred embodiment, the compound selected from list b) is theacid solubility retarding compound. More preferably, the acid solubilityretarding compound is an ethoxylated surfactant with C16-C22 carbonchain length and an ethoxylation degree of 30-40 ethylene oxide groups,a thickener, or combinations thereof.

Suitable thickeners for use in the above described invention may be ofsynthetic or biobased, preferably biobased. A suitable syntheticthickener, is for example a polyacrylate. Suitable biobased thickenersare for instance hydrocolloids such as pectin, agar, carrageenan,alginate, starch, locust bean gum, gelatin, guar gum, gum Arabic,xanthan gum, 12-hydroxy stearic acid. Derivatives of the previouslylisted compounds may also be used. They include carboxymethylcellulose,carboxymethyl guar gum. Evidently, combinations of the thickeners listedabove may also be used.

In a preferred embodiment, the compound selected from list b) is thecompound with melting point between 60° C.-95° C.; preferably between60°-90° C., more preferably between 60°-80° C., most preferably between60°-75° C. Preferably the compound iv) is a nonionic sucrose ester withmelting point between 60° C.-75° C. In another preferred embodiment,compound iv) is a lactide with melting point of approximately 95° C., orcombinations thereof.

In a preferred embodiment, a composition of the invention has a reducedlevel of alkyl benzene sulfonate. More preferably, the composition isfree of alkyl benzene sulfonate. The inventors found that fatty alcoholsulfate is a good substitute for at least part or all of the alkylbenzene sulfonate. In a preferred embodiment of the invention, at leastpart or all of the alkyl benzene sulfonate in the composition isreplaced by fatty alcohol sulfate. The reduction of the use of alkylbenzene sulfonate is advantageous as alkyl benzene sulfonate is apetrochemical which upon aerobic biodegradation leaves stablemetabolites and is not degradable in anaerobic conditions. The use offatty alcohol sulfate in a composition of the invention is advantageousas it has a better ecological profile than alkyl benzene sulfonate. Itprovides good foam. Foam functions as an indicator to a consumer thatthe composition is working. The inventors also found that theextrudability of a composition according to the invention comprising afatty alcohol sulfate is improved.

In a preferred embodiment, a composition of the invention compriseslactide, preferably slow-release lactide. The lactide will liberatelactic acid which will further enhance the lime scale removal claimedin/subject to this invention. Lactic acid is released from aslow-release lactide as follows. A 0.1 w/v % solution of theslow-release lactide in demineralized water at 25° C. is characterizedby a curve depicting pH versus time, wherein the pH is 3.7 after 5minutes, the pH is 3.2 after 10 minutes, and the pH is 2.5 after 120minutes. Slow-release lactide is commercially available from the companyGalactic, Belgium. Use of slow-release lactide is advantageous as it hasthe effect that the release of acid from a composition, i.e. lactide andother acids present, for the prevention or removal of insoluble saltdeposits can be tuned further.

In a preferred embodiment, the composition is formulated as a virtuallywater-free powder, tablet or block.

In such a formulation, the solid state acids used in the presentinvention allow prolonged exposure either due to the product form orthrough delayed acidification. This makes the composition very suitablefor applications such as toilet blocks.

The invention further provides several type compositions for use in theprevention or removal of insoluble salt deposits, including toilet rim,cistern or urinal block; tablets and gels.

In a preferred embodiment, the composition is a toilet rim, cistern orurinal block, comprising: 3-30 weight % itaconic acid, itaconicanhydride, succinic acid, succinic anhydride or a combination thereof,20-50 weight % linear alkyl benzene sulfonate and/or fatty alcoholsulfate, and the remainder formulation auxiliaries. Preferably theformulation auxiliaries comprise or consist of a perfume or fragrance.

In a more preferred embodiment, the toilet rim, cistern or urinal blockas previously described comprises an acid solubility retarding sucrosederivative. In a preferred embodiment, the solubility retarding sucrosederivative is a sucrose behenate, sucrose stearate and/or a fatty acidderived sucrose ester with melting point between 60° C.-75° C. Thelatter is commercially available from P&G, under the trade name Sefose.Use of a sugar based compound in a formulation according to theinvention has for effect that the amount of compounds derived fromrenewable resources is increased further. Sugar based molecules providean improve degradability. The degree of biobased materials used isincreased even further.

In a preferred embodiment, the blocks as described above have a lifeexpectancy of at least 50 flushes, preferably at least 100 flushes, mostpreferably at least 200 flushes.

To a person skilled in the art tests are available for determining thelife expectancy characterizing a batch of products. A test can becarried out as follows: A product is weighed. It is set in a toilet nearthe water supply means, at a precisely defined place. The toilet is fedwith 35° THF hard water reproducing unfavorable but realisticconditions. The toilet is flushed at irregular time intervals. The testis carried out until the product is completely consumed. From the numberof flushes required to consume the product, the product life expectancyis obtained. The life expectancy can be expressed in number of flushes,number of days or number of weeks.

In another preferred embodiment of the invention, the composition aspreviously described is provided in the form of an effervescent tablet.In particular, the effervescent tablet comprises: 7-75% itaconic acid,itaconic anhydride, succinic acid, succinic anhydride or a combinationthereof, 5-25% of a carbonate source, selected from the list of sodiumcarbonate, bicarbonate, percarbonate and combinations thereof, and theremainder formulation auxiliaries. Preferably the formulationauxiliaries comprise or consist of a perfume or fragrance.

In a preferred embodiment of the invention, a 20 gram tablet dissolvesin one liter of water in under 15 minutes and the pH of the resultingwater comprising the dissolved table is at most 4.5, preferably at most4.0, more preferably at most 3.5. Preferably the pH-development providedby the tablet does not go below 2.0.

In another preferred embodiment of the invention, the composition aspreviously described is provided in the form of a toilet gel. Inparticular, the toilet gel, comprises: 1-30% itaconic acid, succinicacid, or a combination thereof, 2-40% an ethoxylated nonionic surfactantwith an ethoxylation degree of 30-40 ethylene oxide units, a thickenersuch as a polyacrylate, a hydrocolloid, a derivative of a hydrocolloid,or a combination thereof, and the remainder formulation auxiliaries.Preferably the formulation auxiliaries comprise or consist of a perfumeor fragrance.

In a further aspect of the invention uses for the compositions of theinvention are provided. In a preferred embodiment, a compositionaccording to an embodiment of the invention is used for the preventionor removal of lime scale, beer stone, milk stone, barium sulfate,calcium oxalate and combinations thereof.

Preferably the used described previously is one wherein the preventionor removal is directed to a toilet, a laundry machine, a dishwashingmachine, a boiler, a kettle, a coffee-maker, an espresso machine, adairy equipment, a food processing equipment, a beverage processingequipment, an industrial water system, or a well.

In another preferred embodiment of the present invention, thecomposition described here above, is used the removal of insoluble saltdeposits upon prolonged exposure of the insoluble salts to thecomposition.

The invention is however not limited to prolonged exposure of thecomposition, all other types of exposure known by the person skilled inthe art, can also be used. The composition according to the presentinvention is for example also very effective in fast descaling. Ifhowever the composition is applied during prolonged exposure, it is veryeffective for heavy duty removal of thick deposits of insolubles, whichis an advantage.

In a third aspect of the invention, a method for the manufacturing ofcompositions according to the invention is provided. In a preferredembodiment, a method for manufacturing compositions for the preventionor removal of insoluble salt deposits comprises the step of:

selecting an organic acid with two carboxylic acid functional groupsobtainable by fermentation and available in substantially dry powderform, from itaconic acid, itaconic acid anhydride, succinic acid,succinic anhydride or a combination thereof,

mixing the selected organic acid with at least one compound determiningthe release of said acid from said composition, said compound isselected from a list comprising: i) a hygroscopic compound, ii) acarbonate source, iii) an acid solubility retarding compound, iv) acompound with melting point situated between 60° C.-95° C., andcombinations thereof, -extruding or melt casting the mixture obtained ata temperature between 60° C.-95° C., -obtaining the composition for theprevention or removal of insoluble salt deposits in a desirable formsuch as a block, tablet or gel.

In a final aspect, the invention provides a method for the prevention orremoval of insoluble salt deposits comprising the step of:

connecting a composition according to an embodiment of the invention toa supply means of water,

contacting the composition with water from said supply means therebylowering the pH of the water to a pH below 5,

leading the water with pH below 5 over a surface in need of treatment,thereby preventing insoluble salts to deposit on the surface or therebyremoving from the surface insoluble salts deposited on the surface. In apreferred embodiment, the pH is below 4.5; preferably below 4.0; morepreferably below 3.5; and not below pH 2.

Preferably, the composition according to the present invention is usedfor the prevention or removal of insoluble salts in toilet, sanitary,bathroom, laundry and automatic dishwashing machine, boiler, kettle,coffee-maker, dairy equipment, food and beverage processing equipment,industrial water systems and wells, concrete removers and the like.However, the composition is also suitable for other descaling activitiesknown by the person skilled in the art.

The second object is achieved by a toilet block a composition comprisingitaconic acid, its anhydride and or lactide and combinations thereof.

Such a product shows a higher descaling activity than the products knownin the state of the art.

The invention further relates to an effervescent tablet comprising acomposition comprising itaconic acid, its anhydride and or lactide andcombinations thereof.

Such an effervescent tablet can be used for descaling in severalapplications, such as a toilet or a dishwashing machine, or any otherapplication known by the person skilled in the art. The solid characterof lactide and itaconic acid offers a substantial advantage in theformulation of these tablets. However, these tablets will still be ableto dissolve quickly upon contact with water. Also, the fact that theacids used in the composition according to the present invention are soefficient upon prolonged contact, offers a huge advantage for thedifferent applications making use of this effervescent tablet.

This invention also relates to a composition comprising itaconic acid,its anhydride and or lactide and combinations thereof for the preventionor removal of insoluble salt deposits.

The present invention uses a composition comprising itaconic acid, itsanhydride, succinic acid or its anhydride and or lactide andcombinations thereof, for the prevention or removal of insoluble saltdeposits.

The invention is further illustrated and described in more detail in thedescription and examples given below.

DETAILED DESCRIPTION OF THE INVENTION

All of the organic acids shown in table 1 were tested in order to find arenewable acid that had potential as a descaling agent, both in terms offast descaling and descaling upon prolonged contact. Furthermore, it wasimportant that the potential descaling agent had a neutral smell, wasnon-corrosive, and had a solid structure.

When screening various non-corrosive and non-pungent smell acids fortheir applicability in descaling products, the inventors surprisinglyfound a substantially different ranking in acid descaling performancefor short as compared to prolonged exposure.

As described here above, using non-corrosive acids with a non-pungent oreven neutral smell offers clear advantages in the production and usephase, but this fact reduces table 1 to 10, respectively 7 potentialcandidates. Selecting non-corrosive, non-pungent smell acids obtainedfrom fermentation narrows the selection down to 6, 5 of which are solidstate acids, which allows more flexibility in formulating either aliquid end product, a powder or a tablet. This selection is as follows;tartaric, citric, lactic, succinic and itaconic acid as well as lactide,succinic acid and itaconic acid being the subject of the presentinvention and offering clear advantages over all other acids asillustrated in the description of the invention. In contrast withcitric, gluconic and lactic acid, itaconic acid is used exclusively innon-food applications. The recently increased commercial availability ofitaconic acid and lactide make this invention all the more attractive.

When a substantial limescale deposit is attacked by a polybasiccarboxylic acid is it reasonable to assume that provided the deposit“survives” this acid attack i.e. is thick enough to last for severalhours, the calcium concentration at its surface will be high enough asto allow the formation of disalts (or trisalts in the case of citric andphosphoric acid) and the contact time long enough for these ofteninsoluble salts to deposit on the surface, thus forming a greasy layer.Without wanting to be bound by theory the inventors assume this layerslows down further descaling due to inhibited access to the calciumcarbonate underneath. From this and from table 1 one would expect thatalthough non-corrosive and having a neutral smell, tartaric, citric andsuccinic acid will be less suited for the job due to the insolubility oftheir calcium disalts, whereas glycolic and lactic should be bettersuited. This proved not to be correct.

Among the acids that were tested, all featuring the aforementioneddesirable properties, glycolic acid is very efficient in fast descalingbut is far less efficient in prolonged descaling (in example 4, evenmore or less failing in example 2). This is attributed to the observedformation of a greasy layer (as is the case with tartaric and citricacid), but is in contradiction to what one would expect from the highwater solubility of the calcium salt (table 1) and in contradiction towhat its manufacturer claims. Lactic acid does a mediocre job in fastdescaling, but is second best upon prolonged contact. Succinic acidperforms reasonably well in both fast and prolonged descaling, althoughits calcium salts are insoluble. The inventors furthermore surprisinglyfound itaconic acid, although not as yet described as such in patentliterature, to be the best solid acid in fast descaling as well as uponprolonged contact. Likewise lactide, known to fully hydrolyze intolactic acid, was shown to be very effective against limescale, which wasnever described before.

Thus the inventors selected two non-corrosive neutral-smell ingredients,which moreover are fully renewable and are solid state ingredients,allowing polyvalent use; itaconic acid, its anhydride and lactide can beused as such in waterless solid compositions or, in case of itaconicacid, used as a liquid compositions, either alone or in combination withother acids. These products are particularly well suited for heavy dutyremoval for insoluble salt deposits, i.e. requiring prolonged exposurefor complete removal.

Stable effervescent toilet descaling tablets containing substantialamounts of itaconic acid were formulated and shown to be very effective.Preliminary tests showed lactide-itaconic based tablets to be even moreeffective, but present the challenge of gelling due to the highhygroscopy of lactide. As it happens this property is very beneficial informulating toilet rim blocks by extrusion where it will cause an outerlayer or membrane that slows down the overall solubility of the blockthereby imparting a controlled release of the fragrance and thesurfactant in the block. Moreover the melting point of lactide isanticipated to assist in the extrusion process and cause it to functionas a solubility retarder. Finally of course it will act as a slowrelease agent of lactic acid shown to be very effective in removing limescale.

These advantages can be complemented with the excellent limescaleremoving capacity of itaconic acid, which is sufficiently butsubstantially less water soluble than most other acids, a property whichagain is a benefit in retarding the complete dissolution of the toiletrim block. Using itaconic anhydride which slowly releases acid uponcontact with water, may present further benefits in that its meltingpoint is 67-69°, well within the extrusion temperature range, as opposedto succinic anhydride (120° C.), maleic (53° C.) and glutaric anhydride(47-57° C.).

As said here above, the present invention entails solid and liquidtoilet rim blocks. Other products for removing insoluble salt depositsaccording to the present invention include solid in-cistern blocks,urinal blocks, effervescent toilet tablets, toilet gels, bathroomcleaners, liquids removing limescale from hard surfaces, periodiccleaners for automatic dishwashing and laundry machines, boilercleaners, treatment products for water wells, boiler systems and tubing,cleaners for dairy and food equipment, concrete cleaners and removers.

The present invention, in various forms or shapes, is shown to be muchmore effective than the commonly used citric acid for preventing andremoving insoluble salts (e.g. Ca, Mg, limescale) while having neutralodor and color, being non fuming, free of phosphorus, non corrosive tothe skin, non toxic to aquatic life and obtained by fermentation as afully renewable product. Moreover it is non corrosive to the treatedsurfaces among others since it's free of chlorides, thus notrepresenting the risk of possible chloride cracking of stainless steelor embrittlement sometimes experienced in acid chloride systems, norwill it cause spallation (in case of itaconic based formulations).

In order to find a renewable and highly efficient descaling agentaccording to the present invention, the inventors screened various acidsfrom Table 1 for their potential application as descaling agents.

EXAMPLES Example 1

Tartaric (Sigma-Aldrich), malic (Sigma-Aldrich), glycolic (DupontChemicals), itaconic (Alfa Caesar), lactic (Purac), succinic(Sigma-Aldrich) and citric (Brenntag) acid were tested according to theprotocol found in the article “Empfelungen zur Qualitätsbewertung fursaure WC-reiniger” (Qualitatsempfelung des IndustrieverbandesKorperpflege -und Washmittel e.V. (IKW), Referat Putz -und Pflegemittel,Frankfurt a.M., paragraph 6 Gebrauchswertprüfung. SÖFW-journal, 120,Jahrgang 13:94) for their descaling efficiency upon short exposure.

For each product, five oven-dry marble plates (Carrara marble, 75×150×5mm, bought at Van Houten Malle) are weighted on a high precision balanceand subsequently completely immersed during 10 seconds in a glass beakerholding 950 milliliter of a 5% active matter acid solution. The platesare then removed from the liquor, and put in upright position for 10minutes during which the acid is allowed for further action. The platesare subsequently rinsed-off during 30 s with softened tap water, driedat 105° C., allowed to cool in a desiccator and again weighted. Theweight loss due to the exposure to the acid is used as a measure for itsdescaling performance. The 0.14766 gram weight loss due to the exposureto the itaconic acid is used as a measure for its descaling performance.

Prod- Weight (g) uct Plate Before After Difference Ita- 1 154.7922154.6747 0.1175 Average 0.14766 conic (g) acid 2 149.244 149.1075 0.1365standard 0.029775 deviation 3 151.8382 151.6805 0.1577 variation4.959201 coeffi- cient (%) 4 150.6909 150.4966 0.1943 5 153.6839153.5516 0.1323

The same approach was simultaneously followed for the other acids.Finally the average descaling efficiency, the standard deviation andvariation coefficient was calculated for all other acids leading to thefollowing comparative table:

Average variation weight standard coefficient Acid loss (g) deviation(%) Tartaric acid 0.09632 0.035235 2.733622 Malic acid 0.14574 0.0293644.963268 Glycolic acid 0.16294 0.01914 8.512848 Itaconic acid 0.147660.029775 4.959201 Lactic acid 0.12784 0.00771 16.58122 Succinic acid0.13764 0.063322 2.173656 Citric acid 0.10496 0.013478 7.787259

From this table it follows that tartaric and citric acid are notparticularly well suited for fast descaling, whereas glycolic isperforming best, as claimed by its manufacturer. Itaconic acidoutperforms all tested solid acids and all acids obtained fromfermentation.

Example 2

Similar to example 1 the descaling efficiency upon prolonged contact tothe same range of acids is determined. This is done in duplicate withfully immersed marble blocks ((Carrara marble, 20×30×30 mm, bought atVan Houten Malle) according to the modified protocol of “Qualitätsnormenfür saure WC-reiniger” (Qualitätsnormen des Industrieverbandes Putz- andPflegemittel e.V. (IPP), Frankfurt/M (Fassung 1987)), again monitoringweight loss but this time after 24 hours immersion in the acid solution,followed by rinse-off and drying.

Acid Average weight loss (g) Tartaric acid 0.3141 Malic acid 8.73535Glycolic acid 2.62915 Itaconic acid 9.6414 Lactic acid 9.05985 Succinicacid 9.30385 Citric acid 3.8461

Tartaric acid fails again, but this time glycolic and citric acid underperform as well. The other tested acids are more or less equivalent, butagain itaconic acid is performing best among the tested solid acids, infact best of all the tested acids. The marble blocks exposed to tartaricand citric acid, but also albeit to a lesser extent that exposed toglycolic acid were observed to be covered with a greasy layer, assumedto be water insoluble calcium salts of the acid.

Example 3

The experiments of example 1 and 2 were repeated with the same set ofblocks and plates for itaconic acid (5%), lactide (3%), lactide (5%),citric acid (5%) and succinic acid (5%). Solutions were allowed to standuntil complete dissolution of the lactide before the descaling test wasstarted.

The following results were obtained for short contact time descaling ofplates and prolonged contact descaling of blocks (average values and 95%confidence intervals):

Weight Weight Weight Weight Weight difference difference Weightdifference difference difference plates (g) plates (g) difference blocks(g) blocks (g) Descaling agent plates (g) −95% +95% blocks (g) −95% +95%Itaconic acid 5% 0.1115 0.088464 0.134616 7.1586 6.2838 8.0334 Lactide5% 0.1365 0.100986 0.171974 6.0445 5.4793 6.6097 Lactide 3% 0.11290.082268 0.143572 2.9844 2.1723 3.7964 Citric acid 5% 0.0782 0.0596370.096683 3.3186 2.7113 3.9259 Succinic acid 5% 0.0899 0.060463 0.1192977.2479 6.6405 7.8552

Lactide and itaconic acid again prove to be very efficient descalingagents as compared to citric acid both in fast and prolonged exposureconditions, 3% lactide thereby matching the performance of 5% citricacid. As in example 2, succinic acid performs very well upon prolongedexposure, somewhat less so at short exposures.

Example 4

A non factorial, central composite design experiment was set up,combining citric acid, succinic acid, lactic acid, itaconic acid andglycolic acid and testing the descaling efficiency of the mixtures bothat short contact times (on marble plates, protocol as in ex.1) andprolonged contact (on marble blocks, as in ex.2). The required volumesfor filling the beakers were prepared as 3% active matter solutions, 20hours prior to the test. Also the formation of an insoluble layersurrounding the blocks was monitored, scoring no visible layer with ascore of 0 and a clearly distinctive layer with a score of 1. Theexperimental setup and descaling results were as follows (sorted on thevisual presence of an insoluble layer):

cit- suc- lac- ita- gly- Pres- ric cinic tic conic colic Weight lossWeight loss ence of acid acid acid acid acid plates (g) blocks (g) layer0 0 0 3 0 0.10074 5.41945 0 0 3 3 0 3 0.19384 16.7526 0 0 0 3 3 30.18188 15.313051 0 0 3 3 3 0 0.12942 13.6005 0 3 0 3 0 3 0.17068 13.3810 0 3 0 0 0 0.08734 4.705 0 0 0 3 0 0 0.09616 5.2176 0 3 3 3 3 3 0.2650419.6414 0 0 3 0 3 3 0.19244 10.1536 1 1.5 1.5 1.5 1.5 1.5 0.1358410.4738 1 1.5 1.5 1.5 1.5 1.5 0.1304 9.784 1 3 0 0 3 3 0.13424 12.7577 13 3 0 3 0 0.16276 6.7325 1 3 3 3 0 0 0.1333 9.3773 1 3 0 3 3 0 0.1428813.0694 1 3 3 0 0 3 0.1672 10.8451 1 3 0 0 0 0 0.05778 2.2648 1 0 0 0 03 0.11152 4.2873 1

These data were examined using statistical software Statistica(Statsoft, Statistica version 9).

For the short exposure of the plates the following multiple regressionmodel with a correlation coefficient (adjusted R²) of 0.902 wasobtained:

Regressn Coeff. Std. Err. P Mean/Interc. 0.042892 0.010743 0.003146(1)citric acid 0.003786 0.003936 0.361202 (2) succinic acid 0.0131920.005328 0.035219 (3)lactic acid 0.014675 0.004718 0.012515 (4)itaconicacid 0.013405 0.002841 0.00109 (5)glycolic acid 0.015795 0.0047180.008556 1 by 2 0.002217 0.001894 0.271693 2 by 3 −0.00293 0.0018940.155759 2 by 5 0.002077 0.001894 0.301121 3 by 5 0.002299 0.0018940.255727

Succinic, lactic, itaconic and glycolic acid seem to be equallyeffective at descaling, contrary to citric acid which is ineffective asalready illustrated in Ex.1. No significant interactions amongst theacids (synergy or antagonism) were noted.

For the prolonged exposure of the blocks the following multipleregression model for the descaling efficiency was obtained with ancorrelation coefficient (adjusted R²) of 0.994:

Regressn Coeff. Std. Err. P Mean/Interc. 0.317877 0.354173 0.46416(1)citric acid 0.645604 0.132453 0.039607 (2)succinic acid 1.4590040.132453 0.008141 (3)lactic acid 1.629871 0.132453 0.006539 (4)itaconicacid 1.697154 0.132453 0.006036 (5)glycolic acid 1.319771 0.1324530.009923 1 by 2 −0.27364 0.03949 0.020198 1 by 3 −0.09582 0.039490.136041 1 by 4 0.078019 0.03949 0.186854 1 by 5 0.211589 0.039490.033112 2 by 3 0.130106 0.03949 0.081079 2 by 4 −0.36003 0.039490.011818 2 by 5 0.089156 0.03949 0.152536 3 by 4 0.1093 0.03949 0.1095083 by 5 0.136147 0.03949 0.074812 4 by 5 −0.12937 0.03949 0.081891

All acids significantly contribute to descaling, albeit that the effectof citric acid again is only half or less that of the other acids.Itaconic acid performs best as in example 2. Succinic acid combined withcitric or itaconic seems to worsen the descaling, whereas glycolic acidpositively interacts with citric acid.

In the latter experiment with the blocks the formation of an insolublelayer around the blocks after 24 hours exposure was scored 0 for noappreciable deposit and 1 for a clearly distinctive layer. The followingmultiple regression model with an correlation coefficient (adjusted R²)of 0.83 was obtained for the formation of an insoluble layer:

Regressn Coeff. Std. Err. P Mean/Interc. 0.055556 0.148032 0.71528(1)citric acid 0.333333 0.04969 0.000053 (2)succinic acid 0 0.035136 1(3)lactic acid 0 0.04969 1 (4)itaconic acid 0 0.035136 1 (5)glycolicacid 0.333333 0.060858 0.00027 1 by 5 −0.11111 0.023424 0.000788 3 by 5−0.11111 0.023424 0.000788

Citric acid alone and 8 out of 10 of the citric acid containingcombinations result in a distinctive separate layer, as opposed to 4 outof 10 for lactic acid and 5 out of 10 for the other acids. Itaconic acidon the other hand does not cause an insoluble layer to be formed and nordo succinic and lactic acid. Contrary to the claims of its manufacturer,and contrary to what one might expect from the solubility of its calciumsalts, glycolic acid also caused an insoluble layer on itself and incombinations with other acids, unless it is combined with lactic acid.The model further identifies a significant negative interaction ofcitric and glycolic acid, which in this case implies a desirable effect,i.e. less insoluble layer when combining glycolic acid with citric acid,probably causing the significant descaling synergy described above.

Example 5

Effervescent 35 gram tablets F1-F8 with the followed compositions weretableted at press forces of 2-5 ton.

Ingredient Supplier F1 F2 F3 F4 F5 F6 F7 F8 F43 F444 citric anhydrous 8057 10 10 56 0 10 56 56 41 Itaconic acid 0 20 67 50 20 74 58.35 20 20 35Lactide (Galacid Galactic 0 0 0 17 0 0 0 0 0 0 LDPW L50) FAS (Sulfopon12 G) Cognis 5 5 5 5 5 5 5 5 5 5 APG (Glucopon 215) Cognis 0.25 0.250.25 0.25 0 0 0.25 0.25 0 0 Desintegration aid 2 2 2 2 2 2 2 2 2 2Tabletting aid 2 2 2 2 2.25 1.25 2 2 3.25 3.25 Sodium carbonate 11.3511.35 11.35 11.35 11.35 15.35 0 11.35 6.35 11.35 Sodium bicarbonate 0 00 0 0 0 20 0 5 0 Sodium percarbonate 2 2 2 2 2 2 2 0 2 2 Potassiumpersulfate FMC 0 0 0 0 0 0 0 2 0 0 perfume pine 0.4 0.4 0.4 0.4 0.4 0.40.4 0.4 0.4 0.4 Friability (%) 94 96 99 98 97 97 95 95 98 98Desintegration 11 12 4 19 10 5 ′/ 19 >20 10 time (s) after 4 ww climateVol. exp. (%) 4 1 24 −1 5 35 ′/ 3 8 2 4 ww climate Vol % 8 ww 5 32 50Wet 7 / Tab 13 10 2 climate sticky strength insuffic

High concentrations of itaconic acid seem to negatively influencetabletting characteristics, in particular the volume expansion uponclimate chamber storage tests, but it is possible to formulate a stableproduct (e.g. F5, F444) with at least 20% itaconic (e.g. F5) or at least35% itaconic acid (e.g. F444). Lactide-itaconic based tablets presentthe additional challenge of gelling, probably due to the high hygroscopyof lactide. Using itaconic anhydride may further improve stability.

These 35 gram tablets were tested for their long exposure descalingefficiency as in example 2 but dosing one tablet per liter. They werecompared with 2 market reference tablets, reference 1 being based onsulfamic acid (31 g tablet) and reference 2, a 25 gram tablet, bothadjusted to 35 grams for testing the descaling at equal dosage.

F1 (35 g): 80% citric acid 0.2415 F2 (35 g): 57% citric acid + 20%itaconic 0.4084 T F3 (35 g): 10% citric acid + 67% itaconic 0.7367 F4(35 g): 10% citric acid + 50% itaconic + 17% 0.9614 lactide F6 (35 g):74% itaconic 1.13 Market reference product 1 (35 g) 1.0269 Marketreference product 2 (35 g) 0.6621

These examples clearly demonstrate the descaling superiority over citricacid of itaconic acid and lactide and in particular of theircombination. Using itaconic acid and or lactide allows to match theperformance of the market reference products while refraining fromcorrosive or environmentally hazardous ingredients.

Example 6

Toilet rim block formulations “Rim1” and “Rim2” are taken for referencefrom the Unger guideline recipes for extrusion of 40 gram rim blocks at70-90° C. In formulas Rim3 to 8 the solubility retarding coconut MEA andFAEO are replaced by sucrose esters with a comparable melting point andwith lactide (which has a somewhat higher mp) or itaconic anhydride(with a comparable melting point). In addition to the acid releasingitaconic anhydride and lactide, itaconic acid is formulated in Rim4 andRim8 against limescale (similar to the best descaling effervescenttablet of the previous example). Furthermore polysuccinimide andpersulfate bleach or calcium peroxide slow release bleach are added toRim3 and Rim8.

Rim Rim Rim Rim Rim Rim Rim Rim Ingredient Ingredient Supplier Function1 2 3 4 5 6 7 8 FAS 1218 UFAROL Unger Extrusion aid 31.5 24 31.5 24 2424 24 24 TCT 90 P and improved soft water foaming (mp >200° C.) AOSUfapore Unger Dry foam 1.5 1.5 1.5 1.5 1.5 1.5 TCO booster FAEO (*)TP716 Unger Combined 16 16 extrusion aid and solubility retarder FAEOEmulgator Unger Surface finish 0.5 0.5 0.5 0.5 F8 improver and extrusionaid Sodium Chloride / / Filler for 12.5 12.5 12.5 12.5 12.5 7.5increased block hardness Sodium Sulphate / / Filler 49.25 49 39.5 3542.5 42.5 42.5 35.5 Calcium carbonate / / Filler - 1 Compactation agentLES70 Foam enhancer Unger Liquid foam 0.5 0.5 booster Pine fragrancePine fragrance / Fragrance 3 3 3 3 3 3 3 3 Coconut MEA Ufanon MK UngerSolubility 3.25 Eur-amid EOC retarding FMCM/FL Surfac- mp 75° C. tantsPolysucinimid Baypure Lanxess Hydrolyses 4 DSP to lime dis- grindedpersing agent Calcium Peroxide Ixper 75C Solvay Slow release 4 bleachK-persulfate / FMC Bleach 4 Sodium citrate Complexing 5 agent Itaconicanhydride Slow release 20 (*) descaler, solubility retarding(hygroscopic and mp 67-69° C.) Itaconic acid Descaling 10 agent Lactide(*) Slow release 5 16 16 16 16 descaler, solubility retarding(hygroscopic and mp 94-99° C.) sucrose behenate Sefose PG Solubility 0.52275C Chemicals retarding mp 65° C. sucrose stearate Sefose PGSolubility 0.5 1618H Chemicals retarding mp 71° C. (*) Cooling of theextruder head will be necessary when using high amounts of coconut MEA,TP 716, itaconic anhydride or lactide to maintain pressure in theextruder and avoid the block becoming too soft for cutting. Recipeadjustments due to local variations in requirements and extruderproperties will have to be considered.

Example 7

Trial Trial Trial Trial Trial Composition 1 2 3 4 5 Fatty alcoholsulphate 1218 37 30 30 30 30 Sucrose ester from fatty 10 5 5 5 5 acid,melting point 65° C. Itaconic acid 5 5 5 5 5 Slow release Lactide 2.72.7 2.7 7.5 2.7 Persulfate 0 0 0 0 10 Water 1.3 1.3 1.3 1.3 0.5 NaCl 1616 16 16 16 Sulfate 25 36 36 31.2 25.5 Fragrance 3 4 4 4 5.3 Total 100100 100 100 100 Diameter (mm) 42 42 25 25 25

Tablets produced by extrusion of the compositions listed in Example 7(Trials 1 to 5) provided hard tablets of consistent composition andhomogeneous and consistent appearance. These tablets lasted well above50 flushes. Tablets made according to the above described compositionswherein the slow-release lactide was replaced by standard lactide showedneedle like protrusions, probably caused by lactide crystals.

Example 8

Formulation for dishwashing machine, in analogy with a commercialdishwashing machine composition sold under the brand name Finish,comprises:

85% itaconic acid (replacing citric acid),10% low foaming non-ionic surfactant,0.5% fragrance and4.5% additives, such as phosphonates and/or calcium silicateSuitable surfactants for use in the above formulation are PPG-15 C12-18and PPG-5 Laureth-5 with fatty alcohol alkoxylateBy the term low foaming as described herein it is meant, producing nofoam or a foam which disappears after build up within less than 5minutes.

Example 9

Formulation comprising itaconic acid and between 1-20% of slow-releaselactide, in the form of powder or a 30% solution, for the treatment ofinsoluble salt deposits in expresso machines.

1. Composition in the form of a toilet rim, cistern or urinal block, orin the form of a tablet for the prevention or removal of insoluble saltdeposits comprising: a) an organic acid with two carboxylic acidfunctional groups obtainable by fermentation, selected from the groupconsisting of itaconic acid, itaconic acid anhydride, and combinationsthereof, wherein itaconic acid has a water content of at most 5%, and b)at least one compound determining the release of said acid from saidcomposition, wherein said compound is: i) a hygroscopic compound. 2.Composition according to claim 1, wherein the organic acid is itaconicacid.
 3. Composition according to claim 1, wherein i) the hygroscopiccompound is lactide, an anionic surfactant, such alkyl benzenesulfonate, or combinations thereof.
 4. Composition according to claim 3,wherein at least part or all of the alkyl benzene sulfonate in thecomposition is replaced by fatty alcohol sulfate.
 5. Compositionaccording to claim 1, comprising a slow-release lactide as measurable bythe pH-development of a 0.1 w/v % solution of the slow-release lactidein demineralized water at 25° C. and the curve depicting the pH versustime displaying a pH of 3.7 after 5 minutes, 3.2 after 10 and 2.5 after120 minutes.
 6. Composition according to claim 1, wherein thecomposition is a toilet rim, cistern or urinal block, comprising: 3-30weight % itaconic acid, itaconic anhydride or a combination thereof,20-50 weight % linear alkyl benzene sulfonate and/or fatty alcoholsulfate, and the remainder formulation auxiliaries.
 7. Block comprisingthe composition according to claim 6, comprising an acid solubilityretarding sucrose derivative such as a sucrose behenate, sucrosestearate and/or a fatty acid derived sucrose ester with melting pointbetween 60° C.-75° C.
 8. Block comprising the composition according toclaim 6, with a life expectancy of at least 50 flushes, preferably atleast 100 flushes, most preferably at least 200 flushes.
 9. A method forthe prevention or removal of lime scale, beer stone, milk stone, bariumsulfate, calcium oxalate and combinations thereof comprising applyingthe composition of claim 1 to a surface comprising lime scale, beerstone, milk stone, barium sulfate, calcium oxalate and combinationsthereof.
 10. The method according to claim 9, wherein the surface isselected from the group consisting of a toilet, a laundry machine, adishwashing machine, a boiler, a kettle, a coffee-maker, an espressomachine, a dairy equipment, a food processing equipment, a beverageprocessing equipment, an industrial water system, and a well.
 11. Methodfor manufacturing compositions according to claim 1, for the preventionor removal of insoluble salt deposits comprising the steps of: selectingan organic acid with two carboxylic acid functional groups obtainable byfermentation and available in substantially dry powder form, fromitaconic acid, itaconic acid anhydride or a combination thereof, mixingthe selected organic acid with at least one compound determining therelease of said acid from said composition, wherein said compound is i)a hygroscopic compound, extruding or melt casting the mixture obtainedat a temperature between 60° C.-95° C., obtaining the composition forthe prevention or removal of insoluble salt deposits in a desirable formsuch as a block or tablet.
 12. Method for the prevention or removal ofinsoluble salt deposits comprising the steps of: connecting acomposition according to claim 1 to a supply means of water, contactingthe composition with water from said supply means thereby lowering thepH of the water to a pH below 5, leading the water with pH below 5 overa surface in need of treatment, thereby preventing insoluble salts todeposit on the surface or thereby removing from the surface insolublesalts deposited on the surface.
 13. Composition according to claim 2,wherein i) the hygroscopic compound is lactide, an anionic surfactant,such alkyl benzene sulfonate, or combinations thereof.
 14. Compositionaccording to claim 13, wherein at least part or all of the alkyl benzenesulfonate in the composition is replaced by fatty alcohol sulfate. 15.Composition according to claim 2, comprising a slow-release lactide asmeasurable by the pH-development of a 0.1 w/v % solution of theslow-release lactide in demineralized water at 25° C. and the curvedepicting the pH versus time displaying a pH of 3.7 after 5 minutes, 3.2after 10 and 2.5 after 120 minutes.
 16. Composition according to claim3, comprising a slow-release lactide as measurable by the pH-developmentof a 0.1 w/v % solution of the slow-release lactide in demineralizedwater at 25° C. and the curve depicting the pH versus time displaying apH of 3.7 after 5 minutes, 3.2 after 10 and 2.5 after 120 minutes. 17.Composition according to claim 4, comprising a slow-release lactide asmeasurable by the pH-development of a 0.1 w/v % solution of theslow-release lactide in demineralized water at 25° C. and the curvedepicting the pH versus time displaying a pH of 3.7 after 5 minutes, 3.2after 10 and 2.5 after 120 minutes.
 18. Composition according to claim13, comprising a slow-release lactide as measurable by thepH-development of a 0.1 w/v % solution of the slow-release lactide indemineralized water at 25° C. and the curve depicting the pH versus timedisplaying a pH of 3.7 after 5 minutes, 3.2 after 10 and 2.5 after 120minutes.
 19. Composition according to claim 14, comprising aslow-release lactide as measurable by the pH-development of a 0.1 w/v %solution of the slow-release lactide in demineralized water at 25° C.and the curve depicting the pH versus time displaying a pH of 3.7 after5 minutes, 3.2 after 10 and 2.5 after 120 minutes.